Air cleaner pre-filtration improvement

ABSTRACT

An air filter is provided and may include a first housing and a filter media disposed within the first housing. A second housing may include an inlet port receiving air at a first pressure from the first housing and an outlet port returning the air to the first housing at a second pressure, less than the first pressure. The second housing may remove debris from the air prior to returning the air to the first housing.

FIELD

The present disclosure relates to air filters and, more particularly, toan air filter incorporating a particle separator.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Air filters may be used in conjunction with an engine to provide theengine with a constant supply of clean air during use. For example, anair filter may be positioned upstream of an internal combustion enginein a vehicle to supply an intake manifold of the vehicle and, thus, theinternal combustion engine, with clean air. The internal combustionengine utilizes the air supplied by the intake manifold and air filterand mixes the air with fuel during combustion. Providing the air filterupstream of the intake manifold and internal combustion engine improvesthe efficiency of and prevents damage to the engine by reducing theintake of solid particulate such as, for example, dust, dirt, and otherdebris into combustion chambers of the internal combustion engine.

Air filters typically include a filter media disposed within a housingthat permits the passage of air therethrough between an inlet and anoutlet. The filter media is typically configured to allow air to passfrom the inlet to the outlet while concurrently removing solidparticulate from the air flow. Once cleaned, the air is drawn from thehousing and into the intake manifold for use by the engine duringcombustion while the solid particulate remains in the filter mediaand/or housing of the air filter.

Under normal operating conditions, a conventional air filter adequatelyremoves solid particulate from incoming air prior to expelling cleansedair to the intake manifold and internal combustion engine. However, overtime and/or when operating in dusty, sandy, or otherwise debris-ladenenvironments, the filter media may become clogged with solidparticulate, thereby reducing the effectiveness of the filter media inremoving solid particulate from an air flow. Further, when the filtermedia becomes laden with solid particulate, air flow through the filteris reduced. As a result, the volume of clean air provided to the engineis insufficient, thereby reducing the efficiency of the engine. Onlywhen the air filter is permitted to concurrently remove solidparticulate from air entering the air filter and provide the engine witha sufficient volume of clean air does the engine operate efficiently.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

An air filter is provided and may include a first housing and a filtermedia disposed within the first housing. A second housing may include aninlet port receiving air at a first pressure from the first housing andan outlet port returning the air to the first housing at a secondpressure, less than the first pressure. The second housing may removedebris from the air prior to returning the air to the first housing.

In another configuration, an air filter is provided and may include afirst housing having a first inlet, a second inlet, a first outlet, anda second outlet. A filter media may be disposed within the first housingand may cleanse air received by the first housing at the first inletprior to the air being expelled from the housing at the first outlet. Asecond housing may be fluidly coupled to the first housing at the secondoutlet and may be fluidly coupled to the first housing at the secondinlet. The second housing may cleanse the air received at the firstinlet prior to the air passing through the filter media. The air may bedrawn through the second housing due to a difference in static pressurebetween the second outlet and the second inlet.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is an environmental view of an air filter for use in conjunctionwith an intake manifold and engine;

FIG. 2 is a cross-sectional view of the air filter of FIG. 1 taken alongline 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view of a portion of the air filter of FIG.1 taken along line 3-3 of FIG. 1;

FIG. 4 is a cross-sectional view of a portion of the air filter of FIG.1 taken along line 4-4 of FIG. 3;

FIG. 5 is a partial cross-sectional view of a discharge valve of the airfilter of FIG. 1 shown in a closed state; and

FIG. 6 is a partial cross-sectional lateral view of a discharge valve ofthe air filter of FIG. 1 (rotated 90 degrees relative to FIG. 5), shownin an open state.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto,” “directly connected to,” or “directly coupled to” another elementor layer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

Although the terms first, second, third, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another region,layer or section. Terms such as “first,” “second,” and other numericalterms when used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from the teachingsof the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,”“lower,” “above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

With reference to the figures, an air filter 10 is provided and mayinclude a main-filter assembly 12 and a particle separator 14. Theparticle separator 14 is fluidly coupled to the main-filter assembly 12and cooperates with the main-filter assembly 12 to remove solidparticles from air received by the main-filter assembly 12.

The main-filter assembly 12 may include a housing 16 and a filter media18. The housing 16 may include an air inlet 20 and a clean-air outlet22. The air inlet 20 may be formed tangentially to an inner surface 24(FIG. 2) of the housing 16 to induce a swirl to air entering the housing16 at the air inlet 20. The clean-air outlet 22 may be formed at an end26 of the housing 16 that is substantially perpendicular to the airinlet 20.

In one configuration, the clean-air outlet 22 is fluidly coupled to anengine 28 via an intake manifold 30. As will be described in greaterdetail below, fluidly coupling the clean-air outlet 22 to the engine28—via the intake manifold 30—allows the air filter 10 to provide asupply of clean air to the engine 28 for use by the engine 28 duringcombustion.

The housing 16 may additionally include a separator outlet 32 and aseparator inlet 34 that are fluidly coupled to the particle separator14. Specifically, the separator outlet 32 is fluidly coupled to theparticle separator 14 to supply the particle separator 14 with air whilethe separator inlet 34 is fluidly coupled to the particle separator 14to receive cleansed air from the particle separator 14.

The filter media 18 may be centrally located within the housing 16 andmay include an outer surface 36 and an inner surface 38 separated by acorrugated or pleated filter element 40. The outer surface 36 maycooperate with the inner surface 38 to provide the filter media 18 witha substantially cylindrical shape. The filter element 40 is disposedgenerally between the outer surface 36 and the inner surface 38 of thefilter media 18 and may be formed from any suitable material thatadequately separates solid particulate from air received at the airinlet 20 of the housing 16 while concurrently allowing air to passthrough the filter element 40.

Once the filter media 18 is disposed within the housing 16, the filtermedia 18 defines a so-called “dirty” zone 42 and a so-called “clean”zone 44. The dirty zone 42 is in fluid communication with the air inlet20 and receives ambient air from an area generally surrounding the airfilter 10. The air received at the air inlet 20 is referred to as“dirty,” as the ambient air likely contains solid particulate 45 (FIGS.5 and 6) such as, for example, dust, dirt, and other debris. The areaidentified by reference number 44 is referred to as the “clean” zone, asair received at the air inlet 20 of the housing 16 first passes throughthe filter media 18 prior to entering the clean zone 44 and, therefore,is substantially free from solid particulate 45. In short, the airdisposed within the dirty zone 42 may be laden with solid particulate 45while the air disposed within the clean zone 44 is clean.

With particular reference to FIGS. 3-6, the particle separator 14 isshown as including a housing 46 and a discharge valve 48. The housing 46may include a substantially cylindrical shape and, further, may includean inlet 50 and an outlet 52. The housing 46 may additionally include abaffle 54, as well as a cone-shaped extension 56.

The inlet 50 may be positioned relative to the housing 46 such that theinlet 50 is substantially tangential to an inner surface 58 of thehousing 46. As such, air received at the inlet 50 engages the innersurface 58 of the housing 46, thereby causing the incoming air to swirlwithin the housing 46. The baffle 54 may be positioned relative to theinner surface 58 such that a gap 60 is provided between an outer surface62 of the baffle 54 and the inner surface 58 of the housing 46. In oneconfiguration, the baffle 54 includes a substantially circular shapethat mimics the substantially circular cross-section of the housing 46such that the outer surface 62 of the baffle 54 is substantially evenlyspaced from the inner surface 58 of the housing 46. The baffle 54 maycooperate with the inner surface 58 to provide a first path 64 definedgenerally by the gap 60 that receives and directs air within the housing46 when air is introduced into the housing 46 at the inlet 50.

While the baffle 54 is described as including a substantially circularshape and, further, as including a shape that substantially mimics thecylindrical shape of the housing 46, the baffle 54 may include a firstend 66 and a second end 68, whereby the first end 66 is separated fromthe second end 68 to define an opening 70 extending through the baffle54. In one configuration, the first end 66 is spaced apart and separatedfrom the second end 68 to define a width of the opening 70 and, further,overlaps the second end 68 when viewed in cross-section (FIG. 4).

The cone-shaped extension 56 may include a surface 72 that is formed atan angle (β) relative to a longitudinal axis 74 of the housing 46. Thesurface 72 may extend from the inner surface 58 of the housing 46 to anopening 76 located at a distal end of the cone-shaped extension 56. Theopening 76 may be aligned with the outlet 52 of the housing 46 such thatthe longitudinal axis 74 passes through the centers of the outlet 52 andthe opening 76. Additionally, because the surface 72 is formed at anangle (β) relative to the longitudinal axis 74 of the housing 46, apocket 78 may be formed between an inner surface 80 of the housing 46located proximate to the discharge valve 48 and an outer surface 82 ofthe cone-shaped extension 56.

With particular reference to FIGS. 5 and 6, the discharge valve 48 isshown to include a normally open valve member 84 movable between aclosed state (FIG. 5) and an open state (FIG. 6). The valve member 84may include a channel 86 shaped to receive a distal end 88 (FIG. 3) ofthe housing 46. In one configuration, the distal end 88 may include alocalized thick spot or flange that is matingly received by the channel86 of the valve member 84 to retain the valve member 84 in a desiredposition relative to the housing 46. Further, the channel 86 may besized such that the valve member 84 must be slightly expanded in orderto accommodate the distal end 88 of the housing 46 to increase thefrictional engagement between the valve member 84 and the housing 46.The valve member 84 may be formed from an elastomeric material such as,for example, rubber. As such, the material of the valve member 84 mayenhance the frictional engagement between the channel 86 of the valvemember 84 and the distal end 88 of the housing 46 to further retain thevalve member 84 on the housing 46.

The valve member 84 may include a distal end 90 having a pair ofopposing walls 92 that are moved away from one another when the valvemember 84 is in the open state to permit the passage of debris throughthe distal end 90 and between the walls 92. The walls 92 are shown inFIG. 5 as being in contact with one another and are shown as beingpartially separated from one another in FIG. 6, whereby the view shownin FIG. 6 is rotated approximately ninety degrees (90°) relative to theview shown in FIG. 5.

The walls 92 may be brought toward one another until at least a portionof the opposing walls 92 are in contact with one another to move thevalve member 84 from the open state (FIG. 6) to the closed state (FIG.5). In other words, the walls 92 may be moved toward one another untilinner surfaces 94 (FIG. 6) of each wall 92 are in contact with oneanother. Once the inner surfaces 94 of the respective walls 92 are incontact with one another, the discharge valve 48 is in the closed state(FIG. 5) and passage through the distal end 90 of the valve member 84 isrestricted.

The discharge valve 48 may be a normally open, fluidly actuated valvethat responds to pressure changes within the housing 46. Therefore, whenthe housing 46 is at atmospheric pressure, the elastomeric material ofthe valve member 84 may cause the discharge valve 48 to be moved intothe open state (FIG. 6) such that the walls 92 are moved away from oneanother and the inner surfaces 94 of the respective walls 92 areseparated. Conversely, when the housing 46 is subjected to vacuumpressure, a force may be applied to the valve member 84, thereby causingthe walls 92 to move toward one another until the discharge valve 48 ismoved into the closed state (FIG. 5) and the inner surfaces 94 of therespective walls 92 are once again in contact with one another. In thisposition, solid particulate 45 may collect within the valve member 84and is restricted from exiting the housing 46 at the distal end 90.However, when the vacuum applied to the housing 46 is released, thenormally open valve member 84 is returned to the open state (FIG. 6),thereby allowing the solid particulate 45 disposed within the valvemember 84 and housing 46 to be expelled from the discharge valve 48 andhousing 46 via the distal end 90 of the valve member 84.

With particular reference to FIGS. 3-6, operation of the air filter 10will be described in detail. When the engine 28 is operating, a vacuumforce is applied to the air filter 10. Specifically, the engine 28imparts a vacuum on the housing 16, thereby causing ambient air to bedrawn into the housing 16 at the air inlet 20. The incoming air isreceived within the dirty zone 42 of the housing 16 and swirls generallywithin the housing 16. The air engages the filter media 18, which causesa portion of the air to pass through the filter media 18 from the dirtyzone 42 to the clean zone 44. In so doing, solid particulate 45 disposedwithin the ambient air located within the dirty zone 42 is depositedinto or on the filter media 18 prior to the air passing through thefilter media 18 and reaching the clean zone 44. The air disposed withinthe clean zone 44 is likewise subjected to vacuum pressure caused byoperation of the engine 28 and is expelled from the housing 16 via theclean-air outlet 22. The clean air exits the housing 16 at the clean-airoutlet 22 and passes to the engine 28 via the intake manifold 30.

While a portion of the air drawn into the housing 16 at the air inlet 20passes through the filter media 18 and moves from the dirty zone 42 tothe clean zone 44, a portion of the incoming air at the air inlet 20 mayfirst exit the housing 16 at the separator outlet 32. The air exitingthe housing 16 at the separator outlet 32 may be laden with solidparticulate 45 due to the ambient air entering the housing 16 at the airinlet 20 being laden with solid particulate 45. Additionally, becausethe filter media 18 separates solid particulate 45 from air passingthrough the filter media 18, solid particulate 45 trapped by the filtermedia 18 may be released by the filter media 18 and may ultimatelycollect proximate to a bottom portion of the housing 16 and near theseparator outlet 32. Therefore, as air passes through the separatoroutlet 32, the air may collect the solid particulate 45 located withinthe bottom portion of the housing 16 and proximate to the separatoroutlet 32 and may carry the solid particulate 45 out of the housing 16at the separator outlet 32.

A portion of the air disposed within the dirty zone 42 may be drawn intothe separator outlet 32 due to the vacuum pressure exerted on thehousing 16 at the clean-air outlet 22. Specifically, the separatoroutlet 32 may be at a higher pressure than the separator inlet 34 and,as a result, the air located within the dirty zone 42 may be drawn outof the housing 16 at the separator outlet 32, thereby causing the air topass through the particle separator 14. In other words, the differentialstatic pressure within the housing 16 causes air to be drawn out of thehousing 16 at the separator outlet 32 such that the air is drawn throughthe particle separator 14 and ultimately is returned to the housing 16at the separator inlet 34. This phenomenon is further enhanced by airswirling within the housing 16 passing over the separator inlet 34.Specifically, when the swirling air passes over the separator inlet 34,the air imparts a vacuum on the separator inlet 34, which furthercontributes to the pressure difference between the separator outlet 32and the separator inlet 34.

The particulate-laden air drawn from the housing 16 flows through theparticle separator 14 to allow the particle separator 14 to remove theparticulate from the air prior to returning cleansed air to the housing16 via the separator inlet 34. Removing the particulate from the housing16 extends the lifespan of the filter media 18 by removing theparticulate from the housing 16 before the particulate can occlude thefilter media 18 and restrict flow therethrough.

The particulate-laden air drawn from the housing 16 at the separatoroutlet 32 may be communicated to the inlet 50 of the particle separator14 via a conduit 98 (FIG. 1) that fluidly couples the separator outlet32 of the housing 16 to the inlet 50 of the particle separator 14. Theparticle-laden air stream may be received by the housing 46 of theparticle separator 14 at the inlet 50 and may be caused to swirl withinthe housing 46 due to the inlet 50 being positioned substantiallytangent to the inner surface 58 of the housing 46.

The incoming air is caused to swirl generally within the first path 64of the housing 46 due to the swirling motion imparted on the air whenthe air is first introduced into the housing 46 at the inlet 50. Becausethe incoming air is caused to swirl within the first path 64 andsubstantially around the longitudinal axis 74 of the housing 46, theheavier, solid particulate 45 located within the air stream is caused tomove toward the inner surface 58 of the housing and generally away fromthe baffle 54. Once sufficient solid particulate 45 is disposedproximate to the inner surface 58 of the housing 46, the solidparticulate 45 may pass from the first path 64 via an opening 100 andmay be received by the surface 72 of the cone-shaped extension 56.

The solid particulate 45 received by the surface 72 of the cone-shapedextension 56 may travel along the surface 72 until the solid particulate45 encounters the opening 76 of the cone-shaped extension 56. At thispoint, the solid particulate 45 passes through the opening 76 andencounters the discharge valve 48. If the discharge valve 48 is in theclosed state (FIG. 5), the solid particulate 45 collects generallywithin the valve member 84 of the discharge valve 48. Alternatively, ifthe discharge valve 48 is in the open state (FIG. 6), the solidparticulate 45 passes through the valve member 84 at the distal end 90and is released to the atmosphere.

The discharge valve 48 will be in the closed state (FIG. 5) when thehousing 46 is subjected to vacuum pressure caused by operation of theengine 28. Therefore, when the engine 28 is operating, the housing 46 ofthe particle separator 14 will be under vacuum pressure and thedischarge valve 48 will be in the closed state. Alternatively, when theengine 28 ceases operation, the vacuum pressure imparted on the housing46 of the particle separator 14 will be released, thereby allowing thevalve member 84 to return to the open state to release the solidparticulate 45 disposed within the discharge valve 48.

As the air entering the housing 46 swirls within the first path 64 anddeposits solid particulate 45 on the surface 72 of the cone-shapedextension 56, the air may exit the first path 64 via the opening 100 andlikewise may engage the cone-shaped extension 56. The cone-shapedextension 56 may cause the air to additionally swirl within the housing46 due to the surface 72 of the cone-shaped extension 56 being formed atan angle (β) relative to the longitudinal axis 74 of the housing 46. Theair swirling within the housing 46 may exit the housing via a secondpath 102 in a direction (Q). Specifically, the air swirling within thecone-shaped extension 56 of the housing 46 is under vacuum pressure dueto operation of the engine 28. Therefore, the engine 28 may draw the airswirling within the cone-shaped extension 56 in the direction (Q) fromthe housing 46 via the outlet 52. The air may pass by the baffle 54 andmay travel substantially along the longitudinal axis 74 in the direction(Q) until ultimately exiting the housing 46.

The air exiting the housing 46 at the outlet 52 may be received by aconduit 104 (FIG. 1), which may transport the clean air back to thehousing 16 of the main-filter assembly 12. The air may be received bythe housing 16 of the main-filter assembly 12 at the separator inlet 34and may be received within the dirty zone 42. The air received withinthe dirty zone 42 will ultimately pass through the filter media 18 andreach the clean zone 44 prior to being drawn into the engine 28 via theclean-air outlet 22 and intake manifold 30.

As described, the air exiting the particle separator 14 at the outlet 52is substantially free from solid particulate 45, as the solidparticulate 45 has been removed due to the swirling motion imparted onthe air entering the housing 46 by the tangential inlet 50 and the firstpath 64. However, should solid particulate 45 be disposed within the airswirling within the cone-shaped extension 56 of the housing 46, thesolid particulate 45 will be drawn back into the first path 64 via theopening 70 of the baffle 54. Specifically, the second end 68 of thebaffle 54 may extend into the second path 102 and may be positioned toreceive air swirling in the direction (W; FIG. 4). Because the solidparticulate 45 is heavier than the air and, further, because the air isswirling in the direction (W) within the cone-shaped extension 56, thesolid particulate 45 will be forced against an inner surface 106 of thebaffle 54. The solid particulate 45 collecting against the inner surface106 of the baffle 54 may be directed through the opening 70 of thebaffle 54 and, ultimately, may be received within the first path 64.

The solid particulate 45 re-entering the first path 64 via the opening70 may mix with incoming air at the inlet 50, which will cause the solidparticulate 45 to mix with solid particulate 45 entering the housing 46at the inlet 50. As described, solid particulate 45 entering the housing46 at the inlet 50 engages the inner surface 58 of the housing 46 and isultimately expelled from the housing 46 via the opening 100 anddischarge valve 48. Therefore, as air swirling within the cone-shapedextension 56 in the direction (W) exits the housing 46 along the secondpath 102 and in the direction (Q), any solid particulate 45 locatedwithin the air engages the inner surface 106 of the baffle 54 and isultimately directed through the opening 70 by the second end 68 of thebaffle 54 as the air flow exits the housing 46 along the second path102. In short, the particle separator 14 removes most of the solidparticulate 45 disposed within the air received at the inlet 50 and,further, removes any remaining solid particulate 45 disposed within theair as the air exits the particle separator 14 along the second path 102due to the first path 64 being in communication with the second path102.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

What is claimed is:
 1. An air filter comprising: a first housing;wherein said first housing includes a first inlet; wherein said firstinlet is positioned relative to the first housing such that the firstinlet is substantially tangential to an inner surface of the firsthousing to induce a swirl to air entering the first housing at the airinlet; a filter media disposed within said first housing; and a particleseparator having a second housing elongated cylindrically surrounding alongitudinal axis, the second housing including: an inlet port receivingair at a first pressure from said first housing; an outlet portreturning said air to said first housing at a second pressure, less thansaid first pressure, said particle separator operable to remove debrisfrom said air prior to returning said air to said first housing; thesecond housing having a cylindrical outer wall having a first axial endand an opposing second axial end; the first axial end of the cylindricalhousing closed over by a radial wall and having the outlet port formedthrough the radial wall; a baffle substantially circular in shape anddisposed within said second housing, the baffle having a circumferentialaxially extending wall formed on an interior side of the radial wallsurrounding the outlet port and extending axially inwardly from theradial wall of the second housing, the circumferential wall of thebaffle extending circumferentially from a first circumferential end to asecond circumferential end; wherein the inlet port is positionedsubstantially tangential to an inner surface of the second housing suchthat air received at the inlet port circulates within the second housingin a first flow path between the baffle and the inner surface; whereinthe second circumferential end is spaced from the first circumferentialend forming an opening permitting flow communication through the bafflebetween the first flow path and a second flow path.
 2. The air filter ofclaim 1, wherein said first housing includes a first inlet fluidlycoupled to a source of said air.
 3. The air filter of claim 1, whereinsaid first housing includes a first outlet fluidly coupled to said inletport of said second housing and a second inlet fluidly coupled to saidoutlet port of said second housing.
 4. The air filter of claim 3,wherein said second inlet includes a lower static pressure than saidfirst outlet.
 5. The air filter of claim 1, wherein said filter mediaprovides said first housing with a clean portion and a dirty portion,said clean portion providing cleansed air to a second outlet of saidfirst housing.
 6. The air filter of claim 5, wherein said second housingreturns said air to said first housing at said dirty portion.
 7. The airfilter of claim 5, wherein said first housing is fluidly coupled to anintake manifold of an engine, said first housing delivering cleansed airfrom said clean portion to said intake manifold.
 8. The air filter ofclaim 1, wherein said first housing is fluidly coupled to an intakemanifold of an engine, said first housing delivering cleansed air tosaid intake manifold.
 9. The air filter of claim 1, wherein a pressuredifference between said first pressure and said second pressure is theresult of a differential static pressure within said first housing. 10.The air filter of claim 1, wherein said first housing is under vacuumpressure.
 11. The air filter of claim 10, wherein said vacuum pressurecauses said air to be drawn into said first housing.
 12. The air filterof claim 11, wherein a first portion of said air drawn into said firsthousing is drawn through said second housing prior to passing throughsaid filter media and a second portion of said air drawn into said firsthousing passes directly though said filter media without first passingthough said second housing.
 13. An air filter comprising: a firsthousing having a first inlet, a second inlet, a first outlet, and asecond outlet; wherein said first inlet is positioned relative to thefirst housing such that the first inlet is substantially tangential toan inner surface of the first housing to induce a swirl to air enteringthe first housing at the air inlet; a filter media disposed within saidfirst housing and operable to cleanse air received by said first housingat said first inlet prior to said air being expelled from said housingat said first outlet; and a particle separator having a second housingfluidly coupled to said first housing at said second outlet and fluidlycoupled to said first housing at said second inlet, said second housingoperable to cleanse said air received at said first inlet prior to saidair passing through said filter media, said air being drawn through saidsecond housing due to a difference in static pressure between saidsecond outlet and said second inlet, the second housing including abaffle substantially circular in shape and disposed within said secondhousing, the baffle having a circumferential axially extending wallformed on an interior side of the radial wall and extending axiallyinwardly from the radial wall, the circumferential wall of the baffleextending circumferentially from a first circumferential end to a secondcircumferential end; wherein the second circumferential end is spacedfrom the first circumferential end forming an opening permitting flowcommunication through the baffle between a first flow path and a secondflow path.
 14. The air filter of claim 13, wherein a first portion ofsaid air received at said first inlet is drawn through said secondhousing prior to passing through said filter media and a second portionof said air received at said first inlet passes directly though saidfilter media without first passing though said second housing.
 15. Theair filter of claim 13, wherein said filter media provides said firsthousing with a clean portion and a dirty portion, said clean portionproviding cleansed air to said first outlet.
 16. The air filter of claim15, wherein said second housing returns said air to said first housingat said dirty portion.
 17. The air filter of claim 15, wherein saidfirst housing is fluidly coupled to an intake manifold of an engine,said first housing delivering cleansed air from said clean portion tosaid intake manifold at said first outlet.
 18. The air filter of claim13, wherein said first housing is fluidly coupled to an intake manifoldof an engine, said first housing delivering cleansed air to said intakemanifold at said first outlet.